3 * Copyright (C) 2002, 2003, 2005, 2006, 2007, 2008,
4 * 2009, 2010, 2011 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
9 * This file defines the types and macros associated with the API for
10 * manipulating scratchpads, which are used by perl to store lexical
11 * variables, op targets and constants.
14 /* offsets within a pad */
16 typedef SSize_t PADOFFSET; /* signed so that -1 is a valid value */
17 #define NOT_IN_PAD ((PADOFFSET) -1)
19 /* B.xs expects the first members of these two structs to line up
20 (xpadl_max with xpadnl_fill).
24 SSize_t xpadl_max; /* max index for which array has space */
26 PAD ** xpadlarr_alloc; /* Pointer to beginning of array of AVs.
27 Note that a 'padnamelist *' is stored
28 in the 0 index of the AV. */
31 PAD * pad_1; /* this slice of PAD * array always alloced */
32 PAD * pad_2; /* maybe unalloced */
33 } * xpadlarr_dbg; /* for use with a C debugger only */
35 U32 xpadl_id; /* Semi-unique ID, shared between clones */
36 U32 xpadl_outid; /* ID of outer pad */
40 SSize_t xpadnl_fill; /* max index in use */
41 PADNAME ** xpadnl_alloc; /* pointer to beginning of array */
42 SSize_t xpadnl_max; /* max index for which array has space */
43 PADOFFSET xpadnl_max_named; /* highest index with len > 0 */
47 /* PERL_PADNAME_MINIMAL uses less memory, but on some platforms
48 PERL_PADNAME_ALIGNED may be faster, so platform-specific hints can
49 define one or the other. */
50 #if defined(PERL_PADNAME_MINIMAL) && defined (PERL_PADNAME_ALIGNED)
51 # error PERL_PADNAME_MINIMAL and PERL_PADNAME_ALIGNED are exclusive
54 #if !defined(PERL_PADNAME_MINIMAL) && !defined(PERL_PADNAME_ALIGNED)
55 # define PERL_PADNAME_MINIMAL
58 #define _PADNAME_BASE \
60 HV * xpadn_ourstash; \
62 HV * xpadn_typestash; \
76 struct padname_with_str {
77 #ifdef PERL_PADNAME_MINIMAL
80 struct padname xpadn_padname;
87 #define PADNAME_FROM_PV(s) \
88 ((PADNAME *)((s) - STRUCT_OFFSET(struct padname_with_str, xpadn_str)))
91 /* a value that PL_cop_seqmax is guaranteed never to be,
92 * flagging that a lexical is being introduced, or has not yet left scope
94 #define PERL_PADSEQ_INTRO U32_MAX
95 #define COP_SEQMAX_INC \
97 (void)(PL_cop_seqmax == PERL_PADSEQ_INTRO && PL_cop_seqmax++))
100 /* B.xs needs these for the benefit of B::Deparse */
101 /* Low range end is exclusive (valid from the cop seq after this one) */
102 /* High range end is inclusive (valid up to this cop seq) */
104 #define COP_SEQ_RANGE_LOW(pn) (pn)->xpadn_low
105 #define COP_SEQ_RANGE_HIGH(pn) (pn)->xpadn_high
106 #define PARENT_PAD_INDEX(pn) (pn)->xpadn_low
107 #define PARENT_FAKELEX_FLAGS(pn) (pn)->xpadn_high
109 /* Flags set in the SvIVX field of FAKE namesvs */
111 #define PAD_FAKELEX_ANON 1 /* the lex is declared in an ANON, or ... */
112 #define PAD_FAKELEX_MULTI 2 /* the lex can be instantiated multiple times */
114 /* flags for the pad_new() function */
116 #define padnew_CLONE 1 /* this pad is for a cloned CV */
117 #define padnew_SAVE 2 /* save old globals */
118 #define padnew_SAVESUB 4 /* also save extra stuff for start of sub */
120 /* values for the pad_tidy() function */
123 padtidy_SUB, /* tidy up a pad for a sub, */
124 padtidy_SUBCLONE, /* a cloned sub, */
125 padtidy_FORMAT /* or a format */
128 /* flags for pad_add_name_pvn. */
130 #define padadd_OUR 0x01 /* our declaration. */
131 #define padadd_STATE 0x02 /* state declaration. */
132 #define padadd_NO_DUP_CHECK 0x04 /* skip warning on dups. */
133 #define padadd_STALEOK 0x08 /* allow stale lexical in active
134 * sub, but only one level up */
136 /* ASSERT_CURPAD_LEGAL and ASSERT_CURPAD_ACTIVE respectively determine
137 * whether PL_comppad and PL_curpad are consistent and whether they have
140 # define pad_peg(label)
143 # define ASSERT_CURPAD_LEGAL(label) \
145 if (PL_comppad ? (AvARRAY(PL_comppad) != PL_curpad) : (PL_curpad != 0)) \
146 Perl_croak(aTHX_ "panic: illegal pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
147 label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
150 # define ASSERT_CURPAD_ACTIVE(label) \
152 if (!PL_comppad || (AvARRAY(PL_comppad) != PL_curpad)) \
153 Perl_croak(aTHX_ "panic: invalid pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
154 label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
156 # define ASSERT_CURPAD_LEGAL(label)
157 # define ASSERT_CURPAD_ACTIVE(label)
162 /* Note: the following three macros are actually defined in scope.h, but
163 * they are documented here for completeness, since they directly or
164 * indirectly affect pads.
166 =for apidoc m|void|SAVEPADSV |PADOFFSET po
167 Save a pad slot (used to restore after an iteration)
171 XXX DAPM it would make more sense to make the arg a PADOFFSET
173 =for apidoc m|void|SAVECLEARSV |SV **svp
174 Clear the pointed to pad value on scope exit. (i.e. the runtime action of
177 =for apidoc m|void|SAVECOMPPAD
178 save C<PL_comppad> and C<PL_curpad>
181 =for apidoc Amx|PAD **|PadlistARRAY|PADLIST * padlist
182 The C array of a padlist, containing the pads. Only subscript it with
183 numbers >= 1, as the 0th entry is not guaranteed to remain usable.
185 =for apidoc Amx|SSize_t|PadlistMAX|PADLIST * padlist
186 The index of the last allocated space in the padlist. Note that the last
187 pad may be in an earlier slot. Any entries following it will be C<NULL> in
190 =for apidoc Amx|PADNAMELIST *|PadlistNAMES|PADLIST * padlist
191 The names associated with pad entries.
193 =for apidoc Amx|PADNAME **|PadlistNAMESARRAY|PADLIST * padlist
194 The C array of pad names.
196 =for apidoc Amx|SSize_t|PadlistNAMESMAX|PADLIST * padlist
197 The index of the last pad name.
199 =for apidoc Amx|U32|PadlistREFCNT|PADLIST * padlist
200 The reference count of the padlist. Currently this is always 1.
202 =for apidoc Amx|PADNAME **|PadnamelistARRAY|PADNAMELIST * pnl
203 The C array of pad names.
205 =for apidoc Amx|SSize_t|PadnamelistMAX|PADNAMELIST * pnl
206 The index of the last pad name.
208 =for apidoc Amx|SSize_t|PadnamelistREFCNT|PADNAMELIST * pnl
209 The reference count of the pad name list.
211 =for apidoc Amx|void|PadnamelistREFCNT_dec|PADNAMELIST * pnl
212 Lowers the reference count of the pad name list.
214 =for apidoc Amx|SV **|PadARRAY|PAD * pad
215 The C array of pad entries.
217 =for apidoc Amx|SSize_t|PadMAX|PAD * pad
218 The index of the last pad entry.
220 =for apidoc Amx|char *|PadnamePV|PADNAME * pn
221 The name stored in the pad name struct. This returns C<NULL> for a target
224 =for apidoc Amx|STRLEN|PadnameLEN|PADNAME * pn
225 The length of the name.
227 =for apidoc Amx|bool|PadnameUTF8|PADNAME * pn
228 Whether PadnamePV is in UTF-8. Currently, this is always true.
230 =for apidoc Amx|SV *|PadnameSV|PADNAME * pn
231 Returns the pad name as a mortal SV.
233 =for apidoc m|bool|PadnameIsOUR|PADNAME * pn
234 Whether this is an "our" variable.
236 =for apidoc m|HV *|PadnameOURSTASH|PADNAME * pn
237 The stash in which this "our" variable was declared.
239 =for apidoc m|bool|PadnameOUTER|PADNAME * pn
240 Whether this entry belongs to an outer pad. Entries for which this is true
241 are often referred to as 'fake'.
243 =for apidoc m|bool|PadnameIsSTATE|PADNAME * pn
244 Whether this is a "state" variable.
246 =for apidoc m|HV *|PadnameTYPE|PADNAME * pn
247 The stash associated with a typed lexical. This returns the C<%Foo::> hash
250 =for apidoc Amx|SSize_t|PadnameREFCNT|PADNAME * pn
251 The reference count of the pad name.
253 =for apidoc Amx|PADNAME *|PadnameREFCNT_inc|PADNAME * pn
254 Increases the reference count of the pad name. Returns the pad name itself.
256 =for apidoc Amx|void|PadnameREFCNT_dec|PADNAME * pn
257 Lowers the reference count of the pad name.
260 =for apidoc m|SV *|PAD_SETSV |PADOFFSET po|SV* sv
261 Set the slot at offset C<po> in the current pad to C<sv>
263 =for apidoc m|SV *|PAD_SV |PADOFFSET po
264 Get the value at offset C<po> in the current pad
266 =for apidoc m|SV *|PAD_SVl |PADOFFSET po
267 Lightweight and lvalue version of C<PAD_SV>.
268 Get or set the value at offset C<po> in the current pad.
269 Unlike C<PAD_SV>, does not print diagnostics with -DX.
270 For internal use only.
272 =for apidoc m|SV *|PAD_BASE_SV |PADLIST padlist|PADOFFSET po
273 Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist
275 =for apidoc m|void|PAD_SET_CUR |PADLIST padlist|I32 n
276 Set the current pad to be pad C<n> in the padlist, saving
277 the previous current pad. NB currently this macro expands to a string too
278 long for some compilers, so it's best to replace it with
281 PAD_SET_CUR_NOSAVE(padlist,n);
284 =for apidoc m|void|PAD_SET_CUR_NOSAVE |PADLIST padlist|I32 n
285 like PAD_SET_CUR, but without the save
287 =for apidoc m|void|PAD_SAVE_SETNULLPAD
288 Save the current pad then set it to null.
290 =for apidoc m|void|PAD_SAVE_LOCAL|PAD *opad|PAD *npad
291 Save the current pad to the local variable C<opad>, then make the
292 current pad equal to C<npad>
294 =for apidoc m|void|PAD_RESTORE_LOCAL|PAD *opad
295 Restore the old pad saved into the local variable C<opad> by C<PAD_SAVE_LOCAL()>
300 #define PadlistARRAY(pl) (pl)->xpadl_arr.xpadlarr_alloc
301 #define PadlistMAX(pl) (pl)->xpadl_max
302 #define PadlistNAMES(pl) *((PADNAMELIST **)PadlistARRAY(pl))
303 #define PadlistNAMESARRAY(pl) PadnamelistARRAY(PadlistNAMES(pl))
304 #define PadlistNAMESMAX(pl) PadnamelistMAX(PadlistNAMES(pl))
305 #define PadlistREFCNT(pl) 1 /* reserved for future use */
307 #define PadnamelistARRAY(pnl) (pnl)->xpadnl_alloc
308 #define PadnamelistMAX(pnl) (pnl)->xpadnl_fill
309 #define PadnamelistMAXNAMED(pnl) (pnl)->xpadnl_max_named
310 #define PadnamelistREFCNT(pnl) (pnl)->xpadnl_refcnt
311 #define PadnamelistREFCNT_dec(pnl) Perl_padnamelist_free(aTHX_ pnl)
313 #define PadARRAY(pad) AvARRAY(pad)
314 #define PadMAX(pad) AvFILLp(pad)
316 #define PadnamePV(pn) (pn)->xpadn_pv
317 #define PadnameLEN(pn) (pn)->xpadn_len
318 #define PadnameUTF8(pn) 1
319 #define PadnameSV(pn) \
320 newSVpvn_flags(PadnamePV(pn), PadnameLEN(pn), SVs_TEMP|SVf_UTF8)
321 #define PadnameFLAGS(pn) (pn)->xpadn_flags
322 #define PadnameIsOUR(pn) cBOOL((pn)->xpadn_ourstash)
323 #define PadnameOURSTASH(pn) (pn)->xpadn_ourstash
324 #define PadnameTYPE(pn) (pn)->xpadn_type_u.xpadn_typestash
325 #define PadnameHasTYPE(pn) cBOOL(PadnameTYPE(pn))
326 #define PadnamePROTOCV(pn) (pn)->xpadn_type_u.xpadn_protocv
327 #define PadnameREFCNT(pn) (pn)->xpadn_refcnt
328 #define PadnameREFCNT_inc(pn) Perl_padname_refcnt_inc(pn)
329 #define PadnameREFCNT_dec(pn) Perl_padname_free(aTHX_ pn)
330 #define PadnameOURSTASH_set(pn,s) (PadnameOURSTASH(pn) = (s))
331 #define PadnameTYPE_set(pn,s) (PadnameTYPE(pn) = (s))
332 #define PadnameOUTER(pn) (PadnameFLAGS(pn) & PADNAMEf_OUTER)
333 #define PadnameIsSTATE(pn) (PadnameFLAGS(pn) & PADNAMEf_STATE)
334 #define PadnameLVALUE(pn) (PadnameFLAGS(pn) & PADNAMEf_LVALUE)
336 #define PadnameLVALUE_on(pn) (PadnameFLAGS(pn) |= PADNAMEf_LVALUE)
337 #define PadnameIsSTATE_on(pn) (PadnameFLAGS(pn) |= PADNAMEf_STATE)
339 #define PADNAMEf_OUTER 0x01 /* outer lexical var */
340 #define PADNAMEf_STATE 0x02 /* state var */
341 #define PADNAMEf_LVALUE 0x04 /* used as lvalue */
342 #define PADNAMEf_TYPED 0x08 /* for B; unused by core */
343 #define PADNAMEf_OUR 0x10 /* for B; unused by core */
345 /* backward compatibility */
347 # define SvPAD_STATE PadnameIsSTATE
348 # define SvPAD_TYPED PadnameHasTYPE
349 # define SvPAD_OUR(pn) cBOOL(PadnameOURSTASH(pn))
350 # define SvPAD_STATE_on PadnameIsSTATE_on
351 # define SvPAD_TYPED_on(pn) (PadnameFLAGS(pn) |= PADNAMEf_TYPED)
352 # define SvPAD_OUR_on(pn) (PadnameFLAGS(pn) |= PADNAMEf_OUR)
353 # define SvOURSTASH PadnameOURSTASH
354 # define SvOURSTASH_set PadnameOURSTASH_set
355 # define SVpad_STATE PADNAMEf_STATE
356 # define SVpad_TYPED PADNAMEf_TYPED
357 # define SVpad_OUR PADNAMEf_OUR
358 # define PADNAMEt_OUTER PADNAMEf_OUTER
359 # define PADNAMEt_STATE PADNAMEf_STATE
360 # define PADNAMEt_LVALUE PADNAMEf_LVALUE
361 # define PADNAMEt_TYPED PADNAMEf_TYPED
362 # define PADNAMEt_OUR PADNAMEf_OUR
366 # define PAD_SV(po) pad_sv(po)
367 # define PAD_SETSV(po,sv) pad_setsv(po,sv)
369 # define PAD_SV(po) (PL_curpad[po])
370 # define PAD_SETSV(po,sv) PL_curpad[po] = (sv)
373 #define PAD_SVl(po) (PL_curpad[po])
375 #define PAD_BASE_SV(padlist, po) \
376 (PadlistARRAY(padlist)[1]) \
377 ? AvARRAY(MUTABLE_AV((PadlistARRAY(padlist)[1])))[po] \
381 #define PAD_SET_CUR_NOSAVE(padlist,nth) \
382 PL_comppad = (PAD*) (PadlistARRAY(padlist)[nth]); \
383 PL_curpad = AvARRAY(PL_comppad); \
384 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
385 "Pad 0x%" UVxf "[0x%" UVxf "] set_cur depth=%d\n", \
386 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (int)(nth)));
389 #define PAD_SET_CUR(padlist,nth) \
391 PAD_SET_CUR_NOSAVE(padlist,nth);
394 #define PAD_SAVE_SETNULLPAD() SAVECOMPPAD(); \
395 PL_comppad = NULL; PL_curpad = NULL; \
396 DEBUG_Xv(PerlIO_printf(Perl_debug_log, "Pad set_null\n"));
398 #define PAD_SAVE_LOCAL(opad,npad) \
400 PL_comppad = (npad); \
401 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
402 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
403 "Pad 0x%" UVxf "[0x%" UVxf "] save_local\n", \
404 PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
406 #define PAD_RESTORE_LOCAL(opad) \
407 assert(!opad || !SvIS_FREED(opad)); \
409 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
410 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
411 "Pad 0x%" UVxf "[0x%" UVxf "] restore_local\n", \
412 PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
416 =for apidoc m|void|CX_CURPAD_SAVE|struct context
417 Save the current pad in the given context block structure.
419 =for apidoc m|SV *|CX_CURPAD_SV|struct context|PADOFFSET po
420 Access the SV at offset C<po> in the saved current pad in the given
421 context block structure (can be used as an lvalue).
426 #define CX_CURPAD_SAVE(block) (block).oldcomppad = PL_comppad
427 #define CX_CURPAD_SV(block,po) (AvARRAY(MUTABLE_AV(((block).oldcomppad)))[po])
431 =for apidoc m|U32|PAD_COMPNAME_FLAGS|PADOFFSET po
432 Return the flags for the current compiling pad name
433 at offset C<po>. Assumes a valid slot entry.
435 =for apidoc m|char *|PAD_COMPNAME_PV|PADOFFSET po
436 Return the name of the current compiling pad name
437 at offset C<po>. Assumes a valid slot entry.
439 =for apidoc m|HV *|PAD_COMPNAME_TYPE|PADOFFSET po
440 Return the type (stash) of the current compiling pad name at offset
441 C<po>. Must be a valid name. Returns null if not typed.
443 =for apidoc m|HV *|PAD_COMPNAME_OURSTASH|PADOFFSET po
444 Return the stash associated with an C<our> variable.
445 Assumes the slot entry is a valid C<our> lexical.
447 =for apidoc m|STRLEN|PAD_COMPNAME_GEN|PADOFFSET po
448 The generation number of the name at offset C<po> in the current
449 compiling pad (lvalue).
451 =for apidoc m|STRLEN|PAD_COMPNAME_GEN_set|PADOFFSET po|int gen
452 Sets the generation number of the name at offset C<po> in the current
453 ling pad (lvalue) to C<gen>.
458 #define PAD_COMPNAME(po) PAD_COMPNAME_SV(po)
459 #define PAD_COMPNAME_SV(po) (PadnamelistARRAY(PL_comppad_name)[(po)])
460 #define PAD_COMPNAME_FLAGS(po) PadnameFLAGS(PAD_COMPNAME(po))
461 #define PAD_COMPNAME_FLAGS_isOUR(po) PadnameIsOUR(PAD_COMPNAME_SV(po))
462 #define PAD_COMPNAME_PV(po) PadnamePV(PAD_COMPNAME(po))
464 #define PAD_COMPNAME_TYPE(po) PadnameTYPE(PAD_COMPNAME(po))
466 #define PAD_COMPNAME_OURSTASH(po) (PadnameOURSTASH(PAD_COMPNAME_SV(po)))
468 #define PAD_COMPNAME_GEN(po) \
469 ((STRLEN)PadnamelistARRAY(PL_comppad_name)[po]->xpadn_gen)
471 #define PAD_COMPNAME_GEN_set(po, gen) \
472 (PadnamelistARRAY(PL_comppad_name)[po]->xpadn_gen = (gen))
476 =for apidoc m|void|PAD_CLONE_VARS|PerlInterpreter *proto_perl|CLONE_PARAMS* param
477 Clone the state variables associated with running and compiling pads.
482 /* NB - we set PL_comppad to null unless it points at a value that
483 * has already been dup'ed, ie it points to part of an active padlist.
484 * Otherwise PL_comppad ends up being a leaked scalar in code like
486 * threads->create(sub { threads->create(sub {...} ) } );
487 * where the second thread dups the outer sub's comppad but not the
488 * sub's CV or padlist. */
490 #define PAD_CLONE_VARS(proto_perl, param) \
491 PL_comppad = av_dup(proto_perl->Icomppad, param); \
492 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
494 padnamelist_dup(proto_perl->Icomppad_name, param); \
495 PL_comppad_name_fill = proto_perl->Icomppad_name_fill; \
496 PL_comppad_name_floor = proto_perl->Icomppad_name_floor; \
497 PL_min_intro_pending = proto_perl->Imin_intro_pending; \
498 PL_max_intro_pending = proto_perl->Imax_intro_pending; \
499 PL_padix = proto_perl->Ipadix; \
500 PL_padix_floor = proto_perl->Ipadix_floor; \
501 PL_pad_reset_pending = proto_perl->Ipad_reset_pending; \
502 PL_cop_seqmax = proto_perl->Icop_seqmax;
505 =for apidoc Am|PADOFFSET|pad_add_name_pvs|"name"|U32 flags|HV *typestash|HV *ourstash
507 Exactly like L</pad_add_name_pvn>, but takes a literal string
508 instead of a string/length pair.
513 #define pad_add_name_pvs(name,flags,typestash,ourstash) \
514 Perl_pad_add_name_pvn(aTHX_ STR_WITH_LEN(name), flags, typestash, ourstash)
517 =for apidoc Am|PADOFFSET|pad_findmy_pvs|"name"|U32 flags
519 Exactly like L</pad_findmy_pvn>, but takes a literal string
520 instead of a string/length pair.
525 #define pad_findmy_pvs(name,flags) \
526 Perl_pad_findmy_pvn(aTHX_ STR_WITH_LEN(name), flags)
529 * ex: set ts=8 sts=4 sw=4 et: